It is known to impart a surface pattern to certain acrylic pile fabrics by roll embossing, wherein the pile surface is brought into engagement with raised surfaces of the roll to press heated pile fibers into the backing of the fabric and transfer the roll surface pattern into the fabric surface. However, such roll embossing of heated pile fabric products is quite expensive because a different pattern roll is required for each different pattern to be applied to the fabric, and the length of a pattern repeat in the fabric is limited by the circumference of the pattern roll. In addition, it is believed that the patterns produced in acrylic pile fabrics by embossing cannot generally be obtained by roll embossing melt spun thermoplastic yarn fabrics, such as nylon and polyester pile fabrics, due to the difficulty of obtaining the high temperatures required to sufficiently shrink and heat-set the yarns, and the resultant tendency for sticking of the yarns to the embossing roll.
It is known in the dyeing of fabrics to pattern dye a moving fabric by the use of continuously flowing liquid streams of dyestuff which are selectively deflected away from striking the fabric by intersecting streams of air controlled in accordance with pattern information. U.S. Pat. No. 3,969,779 and U.S. Pat. No. 4,059,880 disclose apparatus used for such purpose.
It is generally known to employ apparatus to direct pressurized air or steam into the surface of textile fabrics to alter the location of or modify the thermal properties of fibers or yarns therein to provide a change in the surface appearance of such fabrics. U.S. Pat. No. 3,010,179 discloses apparatus for treating synthetic pile fabrics by directing a plurality of jets of dry steam from headers onto the face of the moving fabric to deflect and deorient the pile fibers in areas contacted by the steam, and the fabric is thereafter dried and heated to heat-set the deflected fibers and provide a visual effect simulating fur pelts. U.S. Pat. No. 2,563,259 discloses a method of patterning a flocked pile fabric by directing plural streams of air into the flocked surface of the fabric, before final curing of the adhesive in which the fibers are embedded, to reorient the pile fibers and produce certain patterns therein. U.S. Pat. No. 3,585,098 discloses aparatus for hot air or dry steam treatment of the pile surface of a fabric to relax stresses in the synthetic fibers and cause a disorientation and curling of the fibers throughout the fabric. U.S. Pat. No. 2,241,222 discloses apparatus having a plurality of jet orifices for directing pressurized air or steam perpendicularly into a fluffy fabric surface to raise and curl the nap or fluff of the fabric. U.S. Pat. No. 2,110,118 discloses a manifold having a narrow slot for directing pressurized air against the surface of a fabric containing groups of tufts to fluff the tufts during a textile treating operation.
Although the patents mentioned in the preceding paragraph indicate generally that pressurized air and steam may be employed to alter the surface appearance of fabrics, it is believed that such prior art devices do not possess sufficient accuracy and precision of control of high temperature gas streams to obtain highly precise and intricate surface patterns with well defined boundaries, but generally can only be used to produce relatively grossly defined surface patterns, or surface fiber modifications or a random, non-defined nature. In addition, the apparatus appear to be limited as to the variety of different patterns that can be produced in the fabrics therewith.
In modifying the surface appearance of a relatively moving substrate, such as a textile fabric, by application of streams of fluid, many difficulties are encountered in controlling the flow, pressure, and direction of the streams with sufficient reliability and accuracy to impart precisely defined and intricate patterns to the textile fabric. In addition to preciseness of pattern definition, difficulties are presented in effectively handling very high temperature fluids while maintaining a uniform temperature in the fluid streams across the width of a moving fabric, as well as in controlling rapid activation and deactivation of heated streams by conventional valves located in the heated fluid flow lines. Also, contaminants in the heated fluid can easily block and clog small individual jet orifices of a pressurized fluid applicator, resulting in down time of the treating apparatus to clear the blockage, and loss of fabric product due to improper patterning by the apparatus during such blockage.